Hi
Does dmesg report any error related to the initialisation of the drivers?
 /Zied


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On Thu, Feb 6, 2020 at 6:16 AM, Poonam Aggrwal
<poonam.aggrwal@nxp.com> wrote:
Thank you Mathieu.

Apologies for delayed response. I have been struggling a bit to get the coresight compiled in and making device tree changes referring to Juno platform.
Right now the driver's are not getting probed.

> -----Original Message-----
> From: Mathieu Poirier <mathieu.poirier@linaro.org>
> Sent: Friday, January 24, 2020 10:32 PM
> To: Poonam Aggrwal <poonam.aggrwal@nxp.com>
> Cc: Coresight ML <coresight@lists.linaro.org>
> Subject: Re: Coresight enablement on NXP ARMv8 device
>
> Hi Poonam,
>
> Please CC the coresight mailing list (as I did) when asking questions
> - there is a lot of well informed people on there that can also help you.
>
> On Thu, 23 Jan 2020 at 22:33, Poonam Aggrwal <poonam.aggrwal@nxp.com>
> wrote:
> >
> > Hello Mathieu
> >
> >
> >
> > Greetings!
> >
> >
> >
> > I have started to take a look at the Linux coresight framework, and get this
> enabled on a NXP ARMv8 device.
> >
> >
> >
> > Can you share some documentation on the configs required to be enabled and
> the device tree nodes?
>
> For V8 we have to reference implementation - ARM Juno and the dragonboard
> 410c.  I highly recommend purchasing the latter (because it is very cheap) in
> order to get an understanding of what a working coresight system look like.  It is
> much easier to start from a working example than nothing at all.
Sure Mathieu, let me get the dragonboard 410c  So for this board the stuff would work pretty much out of box, this is very good.
> that the coresight bindings [1] are full of good examples.  I would also have a
> look at the DT for Juno [2] and the dragonboard[3].  The HOWTO.md [4] on
> github is a really good starting point when you'll get to test things out.
>
> [1].
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.boo
> tlin.com%2Flinux%2Flatest%2Fsource%2FDocumentation%2Fdevicetree%2Fbind
> ings%2Farm%2Fcoresight.txt&amp;data=02%7C01%7Cpoonam.aggrwal%40nxp
> .com%7C85f0d8e123d44ebb68a708d7a0ef23fc%7C686ea1d3bc2b4c6fa92cd99c
> 5c301635%7C0%7C0%7C637154821265667926&amp;sdata=hwovHzXiyLp2szqL
> PYiBnFPdJRGRKnoMT8Z9MgduTzs%3D&amp;reserved=0
> [2].
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.boo
> tlin.com%2Flinux%2Flatest%2Fsource%2Farch%2Farm64%2Fboot%2Fdts%2Far
> m%2Fjuno-
> base.dtsi&amp;data=02%7C01%7Cpoonam.aggrwal%40nxp.com%7C85f0d8e12
> 3d44ebb68a708d7a0ef23fc%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C
> 0%7C637154821265667926&amp;sdata=s%2BwfDTntgyrPnhmUCJTn0CZWsi4HI
> hC3QqX7jGa3SUo%3D&amp;reserved=0
> [3].
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.boo
> tlin.com%2Flinux%2Flatest%2Fsource%2Farch%2Farm64%2Fboot%2Fdts%2Fqco
> m%2Fmsm8916.dtsi&amp;data=02%7C01%7Cpoonam.aggrwal%40nxp.com%7C
> 85f0d8e123d44ebb68a708d7a0ef23fc%7C686ea1d3bc2b4c6fa92cd99c5c30163
> 5%7C0%7C0%7C637154821265667926&amp;sdata=LCtENREzhwSeswwekjUFIuj
> iNnq7Z%2BDpUWqNGJmC3qg%3D&amp;reserved=0
> [4].
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.co
> m%2FLinaro%2FOpenCSD%2Fblob%2Fmaster%2FHOWTO.md&amp;data=02%7
> C01%7Cpoonam.aggrwal%40nxp.com%7C85f0d8e123d44ebb68a708d7a0ef23f
> c%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63715482126566792
> 6&amp;sdata=XxKbwvEBcV3sH5jQKpIMrtbxNnVLcDeCj%2BykNKh4NT4%3D&am
> p;reserved=0
>
> >
> > To start I am looking to enable the ARMv8 ETM tracing.
>
> Before going further I advise you to look at the source and sink configuration on
> your platform.  Up to now we've been working with configurations where
> sources share a single sink (N:1 topology).

In the SoC we are using,
The sources are ETM0/1/2/3 and sinks could be either TPIU, or ETR (memory).
So not it is not like one source one sink topology. Does this answer your Q?

> Newer SoC will have one source per sink (1:1 topology).  At this time only the
> former is supported by the framework.  Supporting 1:1 topologies would require
> a fair amount of refactoring, something we haven't had the opportunity to do
> for lack of HW platform to work with.

Regards
Poonam
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